Multi-layer plasma resistant coating by atomic layer deposition

ABSTRACT

Described herein are articles, systems and methods where a plasma resistant coating is deposited onto a surface of a chamber component using an atomic layer deposition (ALD) process. The plasma resistant coating has a stress relief layer and a rare earth metal-containing oxide layer and uniformly covers features, such as those having an aspect ratio of about 3:1 to about 300:1.

TECHNICAL FIELD

Embodiments of the present disclosure relate to articles, coated chambercomponents and methods of coating chamber components with a multi-layerplasma resistant coating. The plasma ceramic coating has an amorphousstress relief layer and an oxide layer containing one or more rare earthmetals such as a yttrium-containing oxide. Each layer of the coating isformed using atomic layer deposition.

BACKGROUND

Various manufacturing processes expose semiconductor process chambercomponents to high temperatures, high energy plasma, a mixture ofcorrosive gases, high stress, and combinations thereof. These extremeconditions may erode and/or corrode the chamber components, increasingthe chamber components' susceptibility to defects. It is desirable toreduce these defects and improve the components' erosion and/orcorrosion resistance in such extreme environments.

Protective coatings are typically deposited on chamber components by avariety of methods, such as thermal spray, sputtering, ion assisteddeposition (IAD), plasma spray or evaporation techniques. Thesetechniques cannot deposit coatings into certain features of the chambercomponents that have an aspect ratio of about 10:1 to about 300:1 (e.g.,pits, shower head holes, etc.). Failure to coat such features may resultin poor quality film, or a portion of the chamber component not beingcoated at all.

SUMMARY

Some of the embodiments described herein cover an article with a portionhaving an aspect ratio of about 3:1 to about 300:1. The article includesa plasma resistant coating on a surface of the portion of the article.The plasma resistant coating comprises an amorphous stress relief layerhaving a thickness of about 10 nm to about 1.5 μm and a rare earthmetal-containing oxide layer having a thickness of about 10 nm to about1.5 μm, wherein the rare earth metal-containing oxide layer covers theamorphous stress relief layer. The plasma resistant coating uniformlycovers the portion, is resistant to cracking and delamination at atemperature of up to 300° C. and is porosity-free.

In some embodiments, a method includes depositing a plasma resistantcoating onto a surface of a chamber component using an atomic layerdeposition (ALD) process. The ALD process includes depositing anamorphous stress relief layer on the surface using ALD to a thickness ofabout 10 nm to about 1.5 μm and depositing a rare-earth metal-containingoxide layer on the stress relief layer using ALD to a thickness of about10 nm to about 1.5 μm. The plasma resistant coating uniformly covers thesurface of the chamber component, is resistant to cracking anddelamination at a temperature of up to 350° C. and is porosity-free. Insome embodiments, depositing the rare-earth metal-containing oxidecomprises co-depositing a yttrium-containing oxide and an additionalmetal oxide to form a single phase yttrium-containing oxide layer. Theco-depositing may be performed by co-injecting a mixture of a firstprecursor for the yttrium-containing oxide and a second precursor forthe additional metal oxide into a deposition chamber containing thechamber component to cause the first precursor and the second precursorto adsorb onto a surface of the amorphous stress relief layer to form afirst half reaction. Subsequently, an oxygen-containing reactant may beinjected into the deposition chamber to form a second half reaction.

In some embodiments, a method includes depositing a plasma resistantcoating onto a surface of a chamber component using an atomic layerdeposition (ALD) process. The ALD process includes depositing anamorphous stress relief layer on the surface using a plurality of cyclesof the ALD process to a thickness of about 10 nm to about 1.5 μm. TheALD process further includes subsequently depositing a stack ofalternating layers of a rare earth metal-containing oxide and a secondoxide to a thickness of about 10 nm to about 1.5 μm. Each of the layersof the rare earth metal-containing oxide are formed by performing about1-30 cycles of the ALD process and has a thickness of about 1-100angstroms. Each of the layers of the second oxide are formed byperforming 1-2 cycles of the ALD process and has a thickness of about0.5-4 angstroms. The layers of the second oxide prevent crystalformation in the layers of the rare earth metal-containing oxide.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean at leastone.

FIG. 1 depicts a sectional view of a processing chamber.

FIG. 2A depicts one embodiment of a deposition process in accordancewith an atomic layer deposition technique as described herein.

FIG. 2B depicts another embodiment of a deposition process in accordancewith an atomic layer deposition technique as described herein.

FIG. 2C depicts another embodiment of a deposition process in accordancewith an atomic layer deposition technique as described herein.

FIG. 3A illustrates a method for creating a plasma resistant coatingusing atomic layer deposition as described herein.

FIG. 3B illustrates a method for creating a plasma resistant coatingusing atomic layer deposition as described herein.

FIG. 4A depicts a showerhead chamber component, in accordance withembodiments.

FIG. 4B depicts a blown up view of a gas conduit, wherein an interior ofthe gas conduit is coated with a plasma resistant coating as describedherein.

FIG. 4C depicts a thermal pie chamber component, in accordance withembodiments.

FIG. 5 is a chart comparing outgassing in total mass loss (μg/cm²) perminute for different materials.

FIG. 6 is an image of a plasma resistant coating as described herein ona component having a high aspect ratio feature.

FIG. 7A depicts a top down SEM image of a plasma resistant coating asdescribed herein.

FIG. 7B depicts a TEM cross sectional image of the plasma resistantcoating of FIG. 7A.

FIG. 8A depicts a top down SEM image of an ALD coating of Y₂O₃ withoutan Al₂O₃ stress relief layer on an article.

FIG. 8B depicts a cross sectional image of the ALD coating of FIG. 8A onthe article.

FIG. 9 illustrates a cross sectional side view TEM image of a plasmaresistant ceramic coating structure on Al 6061 substrate as describedwith regards to FIG. 2C.

FIG. 10 is a scanning transmission electron microscopy energy-dispersivex-ray spectroscopy (STEM-EDS) line scan of the plasma resistant ceramicsample shown in FIG. 9.

DETAILED DESCRIPTION

Embodiments described herein cover articles, coated chamber componentsand methods where a plasma resistant coating having a stress relieflayer and a rare earth metal-containing oxide layer such as ayttrium-containing oxide layer are deposited on a surface of thecomponents. As used herein, the term plasma resistant means resistant toplasma as well as chemistry and radicals. The surface may be an aluminum(e.g., Al 6061, Al 6063) or ceramic material. The deposition process isan atomic layer deposition (ALD) process that may include co-depositionof precursors for the rare earth metal-containing oxide layer. Theplasma resistant coating may be comprised of a bi-layer stack. Thebi-layer stack may include a stress relief layer of aluminum oxide(Al₂O₃), such as amorphous Al₂O₃, and a yttrium-containing oxide layer.Embodiments herein are described with a yttrium-containing oxide layeras an example. It will be appreciated that the top layer may include anyrare earth metal oxide or single phase or multiple phase mixtures ofrare earth metal oxides (i.e., with or without yttrium).

The thickness of each layer in the multi-layer plasma resistant coatingmay be from about 10 nm to about 1.5 μm. In embodiments, the stressrelief layer (e.g., amorphous Al₂O₃) may have a thickness of about 1.0μm and the rare earth metal-containing oxide layer may have a thicknessof about 50 nm. A ratio of the rare earth metal-containing oxide layerthickness to the stress relief layer thickness may be 200:1 to 1:200.The thickness ratio may be selected in accordance with specific chamberapplications. The coating may be annealed in order to create one, ormore than one, intermediate layer comprising an interdiffused solidstate phase between the two layers. The plasma resistant coating maycoat or cover the surfaces of features in the article having an aspectratio of about 10:1 to about 300:1. The plasma resistant coating mayalso conformally cover such features with a substantially uniformthickness. In one embodiment, the plasma resistant coating has aconformal coverage of the underlying surface that is coated (includingcoated surface features) with a uniform thickness having a thicknessvariation of less than about ±20%, a thickness variation of ±10%, athickness variation of ±5%, or a lower thickness variation.

Embodiments described herein enable high aspect ratio features ofchamber components and other articles to be effectively coated withplasma resistant coatings having a stress relief layer (e.g., amorphousAl₂O₃) and a rare earth metal-containing oxide layer such as ayttrium-containing oxide layer (e.g., Y₂O₃ deposited in a single phasewith another rare earth metal oxide) thereon. The plasma resistantcoatings are conformal within the high aspect ratio feature and maycover the feature with a substantially uniform coating (e.g., with athickness variation of about ±5% or less). The plasma resistant coatingis also very dense with a porosity of about 0% (e.g., the plasmaresistant coating may be porosity-free in embodiments). The plasmaresistant coatings having the stress relief layer and the rare earthmetal-containing oxide layer may be resistant to corrosion and erosionfrom plasma etch chemistries, such as CCl₄/CHF₃ plasma etch chemistries,HCl₃Si etch chemistries and NF₃ etch chemistries. Additionally, theplasma resistant coatings described herein having the stress relieflayer and the rare earth metal-containing oxide layer may be resistantto cracking and delamination at temperatures up to about 350° C. Forexample, a chamber component having the plasma resistant coatingdescribed herein may be used in processes that include heating totemperatures of about 200° C. The chamber component may be thermallycycled between room temperature and the temperature of about 200° C.without introducing any cracks or delamination in the plasma resistantcoating.

ALD allows for a controlled self-limiting deposition of material throughchemical reactions with the surface of the article. Aside from being aconformal process, ALD is also a uniform process. All exposed sides ofthe article, including high aspect ratio features (e.g., about 10:1 toabout 300:1) will have the same or approximately the same amount ofmaterial deposited. A typical reaction cycle of an ALD process startswith a precursor (i.e., a single chemical A) flooded into an ALD chamberand adsorbed onto the surface of the article. The excess precursor isthen flushed out of the ALD chamber before a reactant (i.e., a singlechemical R) is introduced into the ALD chamber and subsequently flushedout. The yttrium-containing oxide layer (or other rare earth metal oxidelayer) in the ceramic coatings may, however, be formed by co-depositionof materials. To achieve this, a mixture of two precursors, such as ayttrium-containing oxide precursor (A) (e.g., Y₂O₃) and another rareearth metal oxide (B) precursor, are co-injected (A_(x)B_(y)) at anynumber of ratios, for example, A90+B10, A70+B30, A50+B50, A30+B70,A10+A90 and so on, into the chamber and adsorbed on the surface of thearticle. In these examples, x and y are expressed in molar ratios (mol%) for Ax+By. For example A90+B10 is 90 mol % of A and 10 mol % of B.Excess precursors are flushed out. A reactant is introduced into the ALDchamber and reacts with the adsorbed precursors to form a solid layerbefore the excess chemicals are flushed out. For ALD, the finalthickness of material is dependent on the number of reaction cycles thatare run, because each reaction cycle will grow a layer of a certainthickness that may be one atomic layer or a fraction of an atomic layer.

Unlike other techniques typically used to deposit coatings on componentshaving high aspect ratio features, such as plasma spray coating and ionassisted deposition, the ALD technique can deposit a layer of materialwithin such features (i.e., on the surfaces of the features).Additionally, the ALD technique produces relatively thin (i.e., 1 μm orless) coatings that are porosity-free (i.e., pin-hole free), which mayeliminate crack formation during deposition. The term “porosity-free” asused herein means absence of any pores, pin-holes, voids, or cracksalong the whole depth of the coating as measured by transmissionelectron microscopy (TEM). The TEM may be performed using a 100 nm thickTEM lamella prepared by focused ion beam milling, with the TEM operatedat 200 kV in bright-field, dark-field, or high-resolution mode. Incontrast, with conventional e-beam IAD or plasma spray techniques,cracks form upon deposition even at thicknesses of 5 or 10 μm and theporosity may be 1-3%.

Process chamber components, such as chamber walls, shower heads,nozzles, plasma generation units (e.g., radiofrequency electrodes withhousings), diffusers and gas lines, would benefit from having theseplasma resistant coatings to protect the components in harsh etchenvironments. Many of these chamber components have aspect ratios thatrange from about 10:1 to about 300:1, which makes them difficult to coatwell using conventional deposition methods. Embodiments described hereinenable high aspect ratio articles such as the aforementioned processchamber components to be coated with plasma resistant coatings thatprotect the articles. For example, embodiments enable the insides of gaslines, the insides of nozzles, the insides of holes in showerheads, andso on to be coated with a rare earth metal-containing oxide ceramiccoating.

FIG. 1 is a sectional view of a semiconductor processing chamber 100having one or more chamber components that are coated with a plasmaresistant coating that has a stress relief layer and a rare earthmetal-containing oxide layer in accordance with embodiments. Theprocessing chamber 100 may be used for processes in which a corrosiveplasma environment having plasma processing conditions is provided. Forexample, the processing chamber 100 may be a chamber for a plasma etcheror plasma etch reactor, a plasma cleaner, plasma enhanced CVD or ALDreactors and so forth. Examples of chamber components that may includethe plasma resistant coating include chamber components with complexshapes and holes having high aspect ratios. Some exemplary chambercomponents include a substrate support assembly 148, an electrostaticchuck (ESC) 150, a ring (e.g., a process kit ring or single ring), achamber wall, a base, a gas distribution plate, a showerhead of aprocessing chamber, gas lines, a nozzle, a lid, a liner, a liner kit, ashield, a plasma screen, a flow equalizer, a cooling base, a chamberviewport, a chamber lid, and so on. The plasma resistant coating, whichis described in greater detail below, is applied by ALD. ALD allows forthe application of a conformal coating of a substantially uniformthickness that is porosity-free on all types of components includingcomponents with complex shapes and features having high aspect ratios.

The plasma resistant coating may be grown or deposited using ALD with aprecursor for the stress relief layer and one or more precursors fordeposition of a rare earth metal-containing oxide or co-deposition of arare earth metal-containing oxide in combination with one or moreadditional oxides to form a rare earth metal-containing oxide layer. Inone embodiment, the rare earth metal-containing oxide layer has apolycrystalline structure. The rare earth metal-containing oxide mayinclude yttrium, tantalum, zirconium and/or erbium. For example, therare earth metal-containing oxide may be yttria (Y₂O₃), erbium oxide(Er₂O₃), zirconium oxide (ZrO₂), tantalum oxide (Ta₂O₅), and so on. Inembodiments, the rare-earth metal-containing oxide is polycrystallineyttria. In other embodiments, the rare-earth metal-containing oxide isamorphous yttria. The rare earth metal-containing oxide may also includealuminum mixed with one or more rare earth elements such as yttrium,zirconium and/or erbium. The additional oxide (or oxides) that may beco-deposited with the rare earth metal-containing oxide to form the rareearth metal-containing oxide layer may include zirconium oxide (ZrO₂),aluminum oxide (Al₂O₃), erbium oxide (Er₂O₃), or a combination thereof.A yttrium-containing oxide layer for the multi-layer plasma resistantcoating may be, for example, Y_(x)Zr_(y)O_(z), Y_(a)Zr_(x)Al_(y)O_(z),Y_(x)Al_(y)O_(z), or Y_(x)Er_(y)O_(z). The yttrium-containing oxide maybe yttria (Y₂O₃) with yttriaite having a cubic structure with spacegroup Ia-3 (206).

In one embodiment, the rare-earth metal-containing oxide layer is one ofY₂O₃, Er₂O₃, Y₃Al₅O₁₂ (YAG), Er₃Al₅O₁₂ (EAG), or Y₄Al₂O₉ (YAM). Therare-earth metal-containing oxide layer may also be YAlO₃ (YAP),Er₄Al₂O₉ (EAM), ErAlO₃ (EAP), a solid-solution of Y₂O₃—ZrO₂ and/or aceramic compound comprising Y₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂.

With reference to the solid-solution of Y₂O₃—ZrO₂, the rare-earthmetal-containing oxide layer may include Y₂O₃ at a concentration of10-90 molar ratio (mol %) and ZrO₂ at a concentration of 10-90 mol %. Insome examples, the solid-solution of Y₂O₃—ZrO₂ may include 10-20 mol %Y₂O₃ and 80-90 mol % ZrO₂, may include 20-30 mol % Y₂O₃ and 70-80 mol %ZrO₂, may include 30-40 mol % Y₂O₃ and 60-70 mol % ZrO₂, may include40-50 mol % Y₂O₃ and 50-60 mol % ZrO₂, may include 60-70 mol % Y₂O₃ and30-40 mol % ZrO₂, may include 70-80 mol % Y₂O₃ and 20-30 mol % ZrO₂, mayinclude 80-90 mol % Y₂O₃ and 10-20 mol % ZrO₂, and so on.

With reference to the ceramic compound comprising Y₄Al₂O₉ and asolid-solution of Y₂O₃—ZrO₂, in one embodiment the ceramic compoundincludes 62.93 molar ratio (mol %) Y₂O₃, 23.23 mol % ZrO₂ and 13.94 mol% Al₂O₃. In another embodiment, the ceramic compound can include Y₂O₃ ina range of 50-75 mol %, ZrO₂ in a range of 10-30 mol % and Al₂O₃ in arange of 10-30 mol %. In another embodiment, the ceramic compound caninclude Y₂O₃ in a range of 40-100 mol %, ZrO₂ in a range of 0.1-60 mol %and Al₂O₃ in a range of 0.1-10 mol %. In another embodiment, the ceramiccompound can include Y₂O₃ in a range of 40-60 mol %, ZrO₂ in a range of30-50 mol % and Al₂O₃ in a range of 10-20 mol %. In another embodiment,the ceramic compound can include Y₂O₃ in a range of 40-50 mol %, ZrO₂ ina range of 20-40 mol % and Al₂O₃ in a range of 20-40 mol %. In anotherembodiment, the ceramic compound can include Y₂O₃ in a range of 70-90mol %, ZrO₂ in a range of 0.1-20 mol % and Al₂O₃ in a range of 10-20 mol%. In another embodiment, the ceramic compound can include Y₂O₃ in arange of 60-80 mol %, ZrO₂ in a range of 0.1-10 mol % and Al₂O₃ in arange of 20-40 mol %. In another embodiment, the ceramic compound caninclude Y₂O₃ in a range of 40-60 mol %, ZrO₂ in a range of 0.1-20 mol %and Al₂O₃ in a range of 30-40 mol %. In other embodiments, otherdistributions may also be used for the ceramic compound.

In one embodiment, an alternative ceramic compound that includes acombination of Y₂O₃, ZrO₂, Er₂O₃, Gd₂O₃ and SiO₂ is used for therare-earth metal-containing oxide layer. In one embodiment, thealternative ceramic compound can include Y₂O₃ in a range of 40-45 mol %,ZrO₂ in a range of 0-10 mol %, Er2O3 in a range of 35-40 mol %, Gd2O3 ina range of 5-10 mol % and SiO2 in a range of 5-15 mol %. In a firstexample, the alternative ceramic compound includes 40 mol % Y₂O₃, 5 mol% ZrO₂, 35 mol % Er₂O₃, 5 mol % Gd₂O₃ and 15 mol % SiO₂. In a secondexample, the alternative ceramic compound includes 45 mol % Y₂O₃, 5 mol% ZrO₂, 35 mol % Er₂O₃, 10 mol % Gd₂O₃ and 5 mol % SiO₂. In a thirdexample, the alternative ceramic compound includes 40 mol % Y₂O₃, 5 mol% ZrO₂, 40 mol % Er₂O₃, 7 mol % Gd₂O₃ and 8 mol % SiO₂.

Any of the aforementioned rare-earth metal-containing oxide layers mayinclude trace amounts of other materials such as ZrO₂, Al₂O₃, SiO₂,B₂O₃, Er₂O₃, Nd₂O₃, Nb₂O₅, CeO₂, Sm₂O₃, Yb₂O₃, or other oxides.

The stress relief layer may include amorphous aluminum oxide or similarmaterial and improves adhesion of the plasma resistant coating to thechamber component as well as thermal resistance to cracking anddelamination of the plasma resistant coating at temperatures up to about350° C. in embodiments or 200° C. or from about 200° C. to about 350° C.

As illustrated, the substrate support assembly 148 has a plasmaresistant coating 136, in accordance with one embodiment. However, itshould be understood that any of the other chamber components, such aschamber walls, showerheads, gas lines, electrostatic chucks, nozzles andothers, may also be coated with the ceramic coating.

In one embodiment, the processing chamber 100 includes a chamber body102 and a showerhead 130 that enclose an interior volume 106. Theshowerhead 130 may include a showerhead base and a showerhead gasdistribution plate. Alternatively, the showerhead 130 may be replaced bya lid and a nozzle in some embodiments, or by multiple pie shapedshowerhead compartments and plasma generation units in otherembodiments. The chamber body 102 may be fabricated from aluminum,stainless steel or other suitable material. The chamber body 102generally includes sidewalls 108 and a bottom 110. Any of the showerhead130 (or lid and/or nozzle), sidewalls 108 and/or bottom 110 may includethe plasma resistant coating.

An outer liner 116 may be disposed adjacent the sidewalls 108 to protectthe chamber body 102. The outer liner 116 may be fabricated and/orcoated with a bi-layer coating. In one embodiment, the outer liner 116is fabricated from aluminum oxide.

An exhaust port 126 may be defined in the chamber body 102, and maycouple the interior volume 106 to a pump system 128. The pump system 128may include one or more pumps and throttle valves utilized to evacuateand regulate the pressure of the interior volume 106 of the processingchamber 100.

The showerhead 130 may be supported on the sidewall 108 of the chamberbody 102. The showerhead 130 (or lid) may be opened to allow access tothe interior volume 106 of the processing chamber 100, and may provide aseal for the processing chamber 100 while closed. A gas panel 158 may becoupled to the processing chamber 100 to provide process and/or cleaninggases to the interior volume 106 through the showerhead 130 or lid andnozzle. Showerhead 130 may be used for processing chambers used fordielectric etch (etching of dielectric materials). The showerhead 130includes a gas distribution plate (GDP) 133 having multiple gas deliveryholes 132 throughout the GDP 133. The showerhead 130 may include the GDP133 bonded to an aluminum base or an anodized aluminum base. The GDP 133may be made from Si or SiC, or may be a ceramic such as Y₂O₃, Al₂O₃,Y₃Al₅O₁₂ (YAG), and so forth. Showerhead 130 and delivery holes 132 maybe coated with a plasma resistant coating as described in more detailbelow with respect to FIGS. 4A and 4B.

For processing chambers used for conductor etch (etching of conductivematerials), a lid may be used rather than a showerhead. The lid mayinclude a center nozzle that fits into a center hole of the lid. The lidmay be a ceramic such as Al₂O₃, Y₂O₃, YAG, or a ceramic compoundcomprising Y₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. The nozzle mayalso be a ceramic, such as Y₂O₃, YAG, or the ceramic compound comprisingY₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. The lid, showerhead base 104,GDP 133 and/or nozzle may all be coated with a plasma resistant coatingaccording to an embodiment.

Examples of processing gases that may be used to process substrates inthe processing chamber 100 include halogen-containing gases, such asC₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃and SiF₄, among others, and other gases such as O₂, or N₂O. Examples ofcarrier gases include N₂, He, Ar, and other gases inert to process gases(e.g., non-reactive gases). The substrate support assembly 148 isdisposed in the interior volume 106 of the processing chamber 100 belowthe showerhead 130 or lid. The substrate support assembly 148 holds thesubstrate 144 during processing. A ring 146 (e.g., a single ring) maycover a portion of the electrostatic chuck 150, and may protect thecovered portion from exposure to plasma during processing. The ring 146may be silicon or quartz in one embodiment.

An inner liner 118 may be coated on the periphery of the substratesupport assembly 148. The inner liner 118 may be a halogen-containinggas resist material such as those discussed with reference to the outerliner 116. In one embodiment, the inner liner 118 may be fabricated fromthe same materials of the outer liner 116. Additionally, the inner liner118 may also be coated with a plasma resistant coating as describedherein.

In one embodiment, the substrate support assembly 148 includes amounting plate 162 supporting a pedestal 152, and an electrostatic chuck150. The electrostatic chuck 150 further includes a thermally conductivebase 164 and an electrostatic puck 166 bonded to the thermallyconductive base by a bond 138, which may be a silicone bond in oneembodiment. An upper surface of the electrostatic puck 166 may becovered by the yttrium-based oxide plasma resistant coating 136 in theillustrated embodiment. The plasma resistant coating 136 may be disposedon the entire exposed surface of the electrostatic chuck 150 includingthe outer and side periphery of the thermally conductive base 164 andthe electrostatic puck 166 as well as any other geometrically complexparts or holes having large aspect ratios in the electrostatic chuck.The mounting plate 162 is coupled to the bottom 110 of the chamber body102 and includes passages for routing utilities (e.g., fluids, powerlines, sensor leads, etc.) to the thermally conductive base 164 and theelectrostatic puck 166.

The thermally conductive base 164 and/or electrostatic puck 166 mayinclude one or more optional embedded heating elements 176, embeddedthermal isolators 174 and/or conduits 168, 170 to control a lateraltemperature profile of the substrate support assembly 148. The conduits168, 170 may be fluidly coupled to a fluid source 172 that circulates atemperature regulating fluid through the conduits 168, 170. The embeddedisolator 174 may be disposed between the conduits 168, 170 in oneembodiment. The heater 176 is regulated by a heater power source 178.The conduits 168, 170 and heater 176 may be utilized to control thetemperature of the thermally conductive base 164. The conduits andheater heat and/or cool the electrostatic puck 166 and a substrate(e.g., a wafer) 144 being processed. The temperature of theelectrostatic puck 166 and the thermally conductive base 164 may bemonitored using a plurality of temperature sensors 190, 192, which maybe monitored using a controller 195.

The electrostatic puck 166 may further include multiple gas passagessuch as grooves, mesas and other surface features that may be formed inan upper surface of the puck 166. These surface features may all becoated with a yttrium-based oxide plasma resistant coating according toan embodiment. The gas passages may be fluidly coupled to a source of aheat transfer (or backside) gas such as He via holes drilled in theelectrostatic puck 166. In operation, the backside gas may be providedat controlled pressure into the gas passages to enhance the heattransfer between the electrostatic puck 166 and the substrate 144.

The electrostatic puck 166 includes at least one clamping electrode 180controlled by a chucking power source 182. The clamping electrode 180(or other electrode disposed in the electrostatic puck 166 or base 164)may further be coupled to one or more RF power sources 184, 186 througha matching circuit 188 for maintaining a plasma formed from processand/or other gases within the processing chamber 100. The RF powersources 184, 186 are generally capable of producing RF signal having afrequency from about 50 kHz to about 3 GHz and a power of up to about10,000 Watts.

FIG. 2A depicts one embodiment of a deposition process in accordancewith an ALD technique to grow or deposit a plasma resistant coating onan article. FIG. 2B depicts another embodiment of a deposition processin accordance with an atomic layer deposition technique as describedherein. FIG. 2C depicts another embodiment of a deposition process inaccordance with an atomic layer deposition technique as describedherein.

Various types of ALD processes exist and the specific type may beselected based on several factors such as the surface to be coated, thecoating material, chemical interaction between the surface and thecoating material, etc. The general principle for the various ALDprocesses comprises growing a thin film layer by repeatedly exposing thesurface to be coated to pulses of gaseous chemical precursors thatchemically react with the surface one at a time in a self-limitingmanner.

FIGS. 2A-2C illustrate an article 210 having a surface. Article 210 mayrepresent various process chamber components (e.g., semiconductorprocess chamber components) including but not limited to a substratesupport assembly, an electrostatic chuck (ESC), a ring (e.g., a processkit ring or single ring), a chamber wall, a base, a gas distributionplate, gas lines, a showerhead, plasma electrodes, a plasma housing, anozzle, a lid, a liner, a liner kit, a shield, a plasma screen, a flowequalizer, a cooling base, a chamber viewport, a chamber lid, adiffuser, and so on. The article 210 may be made from a metal (such asaluminum, stainless steel), a ceramic, a metal-ceramic composite, apolymer, a polymer ceramic composite, mylar, polyester, or othersuitable materials, and may further comprise materials such as AN, Si,SiC, Al₂O₃, SiO₂, and so on.

For ALD, either adsorption of a precursor onto a surface or a reactionof a reactant with the adsorbed precursor may be referred to as a“half-reaction.” During a first half reaction, a precursor is pulsedonto the surface of the article 210 (or onto a layer formed on thearticle 210) for a period of time sufficient to allow the precursor tofully adsorb onto the surface. The adsorption is self-limiting as theprecursor will adsorb onto a finite number of available sites on thesurface, forming a uniform continuous adsorption layer on the surface.Any sites that have already adsorbed with a precursor will becomeunavailable for further adsorption with the same precursor unless and/oruntil the adsorbed sites are subjected to a treatment that will form newavailable sites on the uniform continuous coating. Exemplary treatmentsmay be plasma treatment, treatment by exposing the uniform continuousadsorption layer to radicals, or introduction of a different precursorable to react with the most recent uniform continuous layer adsorbed tothe surface.

In some implementations, two or more precursors are injected togetherand adsorbed onto the surface of an article. The excess precursors arepumped out until an oxygen-containing reactant is injected to react withthe adsorbates to form a solid single phase or multi-phase layer (e.g.,of YAG, a phase of Y₂O₃—ZrO₂, and so on). This fresh layer is ready toadsorb the precursors in the next cycle.

In FIG. 2A, article 210 may be introduced to a first precursor 260 for afirst duration until a surface of article 210 is fully adsorbed with thefirst precursor 260 to form an adsorption layer 214. Subsequently,article 210 may be introduced to a first reactant 265 to react with theadsorption layer 214 to grow a solid stress relief layer 216 (e.g., sothat the stress relief layer 216 is fully grown or deposited, where theterms grown and deposited may be used interchangeably herein). The firstprecursor 260 may be a precursor for aluminum or another metal, forexample.

The first reactant 265 may be oxygen, water vapor, ozone, pure oxygen,oxygen radicals, or another oxygen source if the stress relief layer 216is an oxide. Accordingly, ALD may be used to form the stress relieflayer 216.

In an example where the stress relief layer 216 is an alumina (Al₂O₃)stress relief layer, article 210 (e.g., an A16061 substrate) may beintroduced to a first precursor 260 (e.g., trimethyl aluminum (TMA)) fora first duration until all the reactive sites on the surface areconsumed. The remaining first precursor 260 is flushed away and then afirst reactant 265 of H₂O is injected into the reactor to start thesecond half cycle. A stress relief layer 216 of Al₂O₃ is formed afterH₂O molecules react with the Al containing adsorption layer created bythe first half reaction.

Stress relief layer 216 may be uniform, continuous and conformal. Thestress relief layer 216 may be porosity free (e.g., have a porosity of0) or have an approximately 0 porosity in embodiments (e.g., a porosityof 0% to 0.01%). Layer 216 may have a thickness of less than one atomiclayer to a few atoms in some embodiments after a single ALD depositioncycle. Some metalorganic precursor molecules are large. After reactingwith the reactant 265, large organic ligands may be gone, leaving muchsmaller metal atoms. One full ALD cycle (e.g., that includesintroduction of precursors 260 followed by introduction of reactants265) may result in less than a single atomic layer. For example, anAl₂O₃ monolayer grown by TMA and H₂O typically has a growth rate ofabout 0.9-1.3 A/cycle while the Al₂O₃ lattice constant is a-4.7A andc=13A (for a trigonal structure).

Multiple full ALD deposition cycles may be implemented to deposit athicker stress relief layer 216, with each full cycle (e.g., includingintroducing precursor 260, flushing, introducing reactant 265, and againflushing) adding to the thickness by an additional fraction of an atomto a few atoms. As shown, up to n full cycles may be performed to growthe stress relief layer 216, where n is an integer value greater than 1.In embodiments, stress relief layer 216 may have a thickness of about 10nm to about 1.5 μm. Stress relief layer 216 may have a thickness ofabout 10 nm to about 15 nm in embodiments or about 0.8-1.2 μm in otherembodiments.

The stress relief layer 216 provides robust mechanical properties.Stress relief layer 216 may enhance dielectric strength, may providebetter adhesion of the plasma resistant coating to the component (e.g.,formed of Al6061, Al6063 or ceramic), and may prevent cracking of theplasma resistant coating at temperatures up to about 200° C., or up toabout 250° C., or from about 20° C. to about 250° C. In furtherembodiments, the stress relief layer 216 may prevent cracking of theplasma resistant coating at temperatures of up to about 350° C. Suchmetal articles have a coefficient of thermal expansion that may besignificantly higher than the coefficient of thermal expansion of arare-earth metal-containing oxide layer of the plasma resistant coating.By first applying the stress relief layer 216, the detrimental effect ofmismatch in coefficients of thermal expansion between the article andthe rare-earth metal-containing oxide layer may be managed. Since ALD isused for the deposition, the internal surfaces of high aspect ratiofeatures such as gas delivery holes in a showerhead or a gas deliveryline may be coated, and thus an entirety of a component may be protectedfrom exposure to a corrosive environment.

Layer 216 may be Al₂O₃, such as amorphous Al₂O₃, in embodiments.Amorphous Al₂O₃ has a higher temperature capability than, for example, ayttrium-containing oxide. Therefore, the addition of an amorphous Al₂O₃layer as a stress relief layer under a yttrium-containing oxide layer orother rare-earth metal-containing oxide layer may increase the thermalresistance of the plasma resistant coating as a whole by relieving theelevated stress concentrated at some areas of the yttria/Al6061interface. Moreover, Al₂O₃ has good adhesion to an aluminum basedcomponent because of common elements (i.e., the aluminum). Similarly,Al₂O₃ has good adhesion to rare earth metal-containing oxides alsobecause of common elements (i.e., the oxides). These improved interfacesreduce interfacial defects which are prone to initiate cracks.

Additionally, the amorphous Al₂O₃ layer may act as a barrier thatprevents migration of metal contaminants (e.g., Mg, Cu, etc. tracemetals) from the component or article into the rare earthmetal-containing oxide layer. For example, testing was performed inwhich a copper source layer was deposited over the Al₂O₃ stress relieflayer 216. A secondary ion mass spectroscopy (SIMS) depth profile showsthat no copper diffused into the Al₂O₃ stress relief layer 216 orthrough the Al₂O₃ stress relief layer 216 after annealing at 300C for 4hours.

Subsequently, article 210 having layer 216 may be introduced to anadditional one or more precursors 270 for a second duration until asurface of stress relief layer 216 is fully adsorbed with the one ormore additional precursors 270 to form an adsorption layer 218.Subsequently, article 210 may be introduced to a reactant 275 to reactwith adsorption layer 218 to grow a solid rare-earth metal-containingoxide layer 220, also referred to as the second layer 220 for simplicity(e.g., so that the second layer 220 is fully grown or deposited).Accordingly, the second layer 220 is fully grown or deposited overstress relief layer 216 using ALD. In an example, precursor 270 may be ayttrium containing precursor used in the first half cycle, and reactant275 may be H₂O used in the second half cycle.

The second layer 220 forms the yttrium-containing oxide layer or otherrare-earth metal-containing oxide layer, which may be uniform,continuous and conformal. The second layer 220 may have a very lowporosity of less than 1% in embodiments, and less than 0.1% in furtherembodiments, and about 0% in embodiments or porosity-free in stillfurther embodiments. Second layer 220 may have a thickness of less thanan atom to a few atoms (e.g., 2-3 atoms) after a single full ALDdeposition cycle. Multiple ALD deposition stages may be implemented todeposit a thicker second layer 220, with each stage adding to thethickness by an additional fraction of an atom to a few atoms. As shown,the full deposition cycle may be repeated m times to cause the secondlayer 220 to have a desired thickness, where m is an integer valuegreater than 1. In embodiments, second layer 220 may have a thickness ofabout 10 nm to about 1.5 μm. Second layer 220 may have a thickness ofabout 10 nm to about 20 nm in embodiments or about 50 nm to about 60 nmin some embodiments. In other embodiments, second layer 220 may have athickness of about 90 nm to about 110 nm.

A ratio of the rare earth metal-containing oxide layer thickness to thestress relief layer thickness may be 200:1 to 1:200. A higher ratio ofthe rare earth metal-containing oxide layer thickness to the stressrelief layer thickness (e.g., 200:1, 100:1, 50:1, 20:1, 10:1, 5:1, 2:1etc.) provides better corrosion and erosion resistance, while a lowerratio of the rare earth metal-containing oxide layer thickness to thestress relief layer thickness (e.g., 1:2, 1:5, 1:10, 1:20, 1:50, 1:100,1:200) provides better heat resistance (e.g., improved resistance tocracking and/or delamination caused by thermal cycling). The thicknessratio may be selected in accordance with specific chamber applications.In an example, for a capacitive coupled plasma environment with highsputter rate, a top layer of 1 um may be deposited on a 50 nm stressrelief Al₂O₃ layer. For a high temperature chemical or radicalenvironment without energetic ion bombardment, a top layer of 100 nmwith a bottom layer of 500 nm may be optimal. A thick bottom layer canalso prevent trace metals from diffusing out from the underlyingsubstrate or article that the plasma resistant coating is on.

Second layer 220 may be any of the aforementioned rare-earthmetal-containing oxide layers. For example, second layer 220 may beY₂O₃, alone or in combination with one or more other rare earth metaloxides. In some embodiments, second layer 220 is a single phase materialformed from a mixture of at least two rare earth metal-containing oxideprecursors that have been co-deposited by ALD (e.g., combinations of oneor more of Y₂O₃, Er₂O₃, Al₂O₃ and ZrO₂). For example, second layer 220may be one of Y_(x)Zr_(y)O_(z), Y_(x)Er_(y)O_(z), Y₃Al₅O₁₂ (YAG),Y₄Al₂O₉ (YAM), Y₂O₃ stabilized ZrO₂ (YSZ), or a ceramic compoundcomprising Y₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. In one embodiment,the stress relief layer 216 is amorphous Al₂O₃ and the second layer 220is a polycrystalline or amorphous yttrium-containing oxide compound(e.g., Y₂O₃, Y_(x)Al_(y)O_(z), Y_(x)Zr_(y)O_(z), Y_(x)Er_(y)O_(z)) aloneor in a single phase with one or more other rare earth metal-containingoxide material. Accordingly, stress relief layer 216 may be a stressrelief layer that is deposited prior to deposition of theyttrium-containing oxide layer.

In some embodiments, second layer 220 may include Er₂O₃, Y₂O₃, Al₂O₃, orZrO₂. In some embodiments, second layer 220 is a multi-componentmaterial of at least one of Er_(x)Al_(y)O_(z) (e.g., Er₃Al₅O₁₂),Er_(x)Zr_(y)O_(z), Er_(a)Zr_(x)Al_(y)O_(z), Y_(x)Er_(y)O_(z), orEr_(a)Y_(x)Zr_(y)O_(z) (e.g., a single phase solid solution of Y₂O₃,ZrO₂ and Er₂O₃). Second layer 220 may also be one of Y₃Al₅O₁₂ (YAG),Y₄Al₂O₉ (YAM), Y₂O₃ stabilized ZrO₂ (YSZ), or a ceramic compoundcomprising Y₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. In one embodiment,the second layer 220 is an erbium containing compound (e.g., Er₂O₃,Er_(x)Al_(y)O_(z), Er_(x)Zr_(y)O_(z), Er_(a)Zr_(x)Al_(y)O_(z),Y_(x)Er_(y)O_(z), or Er_(a)Y_(x)Zr_(y)O_(z)).

With reference to FIGS. 2B-2C, in some embodiments, the plasma resistantcoating contains more than two layers. Specifically, the plasmaresistant coating may include a sequence of alternating layers of thestress relief layer and the rare-earth metal-containing oxide layer, ormay include the stress relief layer and a sequence of alternating layersfor the rare-earth metal-containing oxide layer. In some embodiments, arare-earth metal-containing oxide layer is a layer of alternatingsub-layers. For example, a rare-earth metal-containing oxide layer maybe a series of alternating sublayers of Y₂O₃ and Al₂O₃, a series ofalternating sublayers of Y₂O₃ and ZrO₂, a series of alternatingsublayers of Y₂O₃, Al₂O₃ and ZrO₂, and so on.

Referring to FIG. 2B, an article 210 having a stress relief layer 216may be inserted into a deposition chamber. The stress relief layer 216may have been formed as set forth with reference to FIG. 2A. Article 210having stress relief layer 216 may be introduced to one or moreprecursors 280 for a duration until a surface of stress relief layer 216is fully adsorbed with the one or more additional precursors 280 to forman adsorption layer 222. Subsequently, article 210 may be introduced toa reactant 282 to react with adsorption layer 222 to grow a solid metaloxide layer 224. Accordingly, the metal oxide layer 224 is fully grownor deposited over stress relief layer 216 using ALD. In an example,precursor 280 may be a yttrium containing precursor used in the firsthalf cycle, and reactant 282 may be H₂O used in the second half cycle.The metal oxide layer 224 may be a first one of Y₂O₃, ZrO₂, Al₂O₃,Er₂O₃, Ta₂O₅, or another oxide.

Article 210 having stress relief layer 216 and metal oxide layer 224 maybe introduced to one or more precursors 284 for a duration until asurface of metal oxide layer 224 is fully adsorbed with the one or moreprecursors 284 to form an adsorption layer 226. Subsequently, article210 may be introduced to a reactant 286 to react with adsorption layer226 to grow an additional solid metal oxide layer 228. Accordingly, theadditional metal oxide layer 228 is fully grown or deposited over themetal oxide layer 224 using ALD. In an example, precursor 284 may be azirconium containing precursor used in the first half cycle, andreactant 286 may be H₂O used in the second half cycle. The metal oxidelayer 224 may be a second one of Y₂O₃, ZrO₂, Al₂O₃, Er₂O₃, Ta₂O₅, oranother oxide.

As shown, the deposition of the metal oxide 224 and the second metaloxide 228 may be repeated n times to form a stack 237 of alternatinglayers, where n is an integer value greater than 2. N may represent afinite number of layers selected based on the targeted thickness andproperties. The stack 237 of alternating layers may be considered as arare-earth metal-containing oxide layer containing multiple alternatingsub-layers. Accordingly, precursors 280, reactants 284, precursors 284and reactants 286 may be repeatedly introduced sequentially to grow ordeposit additional alternating layers 230, 232, 234, 236, and so on.Each of the layers 224, 224, 230, 232, 234, 236, and so on may be verythin layers having a thickness of less than a single atomic layer to afew atomic layers. For example, an Al₂O₃ monolayer grown by TMA and H₂Otypically has a growth rate of about 0.9-1.3 A/cycle while the Al₂O₃lattice constant is a-4.7 A and c=13 A (for a trigonal structure).

The alternating layers 224-236 described above have a 1:1 ratio, wherethere is a single layer of a first metal oxide for each single layer ofa second metal oxide. However, in other embodiments there may be otherratios such as 2:1, 3:1, 4:1, and so on between the different types ofmetal oxide layers. For example, two Y₂O₃ layers may be deposited forevery ZrO₂ layer in an embodiment. Additionally, the stack 237 ofalternating layers 224-236 have been described as an alternating seriesof two types of metal oxide layers. However, in other embodiments morethan two types of metal oxide layers may be deposited in an alternatingstack 237. For example, the stack 237 may include three differentalternating layers (e.g., a first layer of Y₂O₃, a first layer of Al₂O₃,a first layer of ZrO₂, a second layer of Y₂O₃, a second layer of Al₂O₃,a second layer of ZrO₂, and so on).

After the stack 237 of alternating layers has been formed, an annealprocess may be performed to cause the alternating layers of differentmaterials to diffuse into one another and form a complex oxide having asingle phase or multiple phases. After the annealing process, the stackof alternating layers 237 may therefore become a single rare-earthmetal-containing oxide layer 238. For example, if the layers in thestack are Y₂O₃, Al₂O₃, and ZrO₂, then the resulting rare-earthmetal-containing oxide layer 238 may a ceramic compound comprisingY₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. If the layers in the stackare Y₂O₃ and ZrO₂, then be a solid-solution of Y₂O₃—ZrO₂ may be formed.

Referring to FIG. 2C, an article 210 having a stress relief layer 216may be inserted into a deposition chamber. The stress relief layer 216may have been formed as set forth with reference to FIG. 2A. Article 210having stress relief layer 216 may be introduced to one or moreprecursors 290 for a duration until a surface of stress relief layer 216is fully adsorbed with the one or more precursors 290 to form anadsorption layer 240. Subsequently, article 210 may be introduced to areactant 292 to react with adsorption layer 240 to grow a solid rareearth oxide layer 242. The precursors 290 and reactant 292 maycorrespond to precursors 270 and reactant 275 in embodiments.Accordingly, the rare earth oxide layer 242 is fully grown or depositedover stress relief layer 216 using ALD. The process of introducing theprecursors 290 and then the reactant 292 may be repeated n times tocause the rare earth oxide layer 242 to have a desired thickness, wheren is an integer greater than 1.

Article 210 having stress relief layer 216 and rare earth oxide layer242 may be introduced to one or more precursors 294 for a duration untila surface of rare earth oxide layer 242 is fully adsorbed with the oneor more precursors 294 to form an adsorption layer 244. Subsequently,article 210 may be introduced to a reactant 296 to react with adsorptionlayer 244 to grow a barrier layer 246. The precursors 294 and reactants296 may correspond to precursors 260 and reactants 265 in embodiments.Accordingly, the barrier layer 244 may have a same material compositionas the stress relief layer 216. The barrier layer 246 is fully grown ordeposited over the rare earth oxide layer 242 using ALD. The process ofintroducing the precursors 294 and then the reactant 296 may beperformed one or two times to form a thin barrier layer 246 that mayprevent crystal growth in the rare earth oxide layers.

As shown, the deposition of the rare earth oxide 242 and the barrierlayer 228 may be repeated m times to form a stack 248 of alternatinglayers, where m is an integer value greater than 1. N may represent afinite number of layers selected based on the targeted thickness andproperties. The stack 248 of alternating layers may be considered as arare-earth metal-containing oxide layer containing multiple alternatingsub-layers.

The final structure shown in FIG. 2C is a cross sectional side view ofan article 210 coated with a plasma resistant coating that comprises anamorphous stress relief layer 216 and a stack 248 of alternating layersof a rare earth metal-containing oxide 242 and a second oxide or otherceramic 228. The amorphous stress relief layer 216 may have a thicknessof about 10 nm to about 1.5 μm. In embodiments, the stress relief layermay have a thickness of about 10-100 nm. In further embodiments, thestress relief layer 216 may have a thickness of about 20-50 nm. In stillfurther embodiments, the stress relief layer 216 may have a thickness ofabout 20-30 nm.

The second oxide or other ceramic may be a same oxide as an oxide usedto form the stress relief layer (e.g., Al₂O₃) in some embodiments.Alternatively, the second oxide or ceramic may be a different oxide thanthe oxide used to form the stress relief layer.

Each layer of the rare earth metal-containing oxide may have a thicknessof about 5-10 angstroms and may be formed by performing about 5-10cycles of an ALD process, where each cycle forms a nanolayer (orslightly less or more than a nanolayer) of the rare earthmetal-containing oxide. In one embodiment, each layer of the rare-earthmetal-containing oxide is formed using about 6-8 ALD cycles. Each layerof the second oxide or other ceramic may be formed from a single ALDcycle (or a few ALD cycles) and may have a thickness of less than anatom to a few atoms. Layers of the rare earth metal-containing oxide mayeach have a thickness of about 5-100 angstroms, and layers of the secondoxide may each have a thickness of about 1-20 angstroms in embodiments,and a thickness of 1-4 angstroms in further embodiments. The stack 248of alternating layers of the rare earth metal-containing oxide 242 andthe second oxide or other ceramic 228 may have a total thickness ofabout 10 nm to about 1.5 μm. In further embodiments, the stack 248 mayhave a thickness of about 100 nm to about 1.5 μm. In furtherembodiments, the stack 248 may have a thickness of about 100 nm to about300 nm, or about 100-150 nm. The thin layers of the second oxide orother ceramic 246 between the layers 242 of the rare earthmetal-containing oxide may prevent crystal formation in the rare earthmetal-containing oxide layers. This may enable an amorphous yttria layerto be grown.

FIGS. 9-10 illustrate measurement data for an manufactured in accordancewith the technique described in FIG. 2C.

In the embodiments described with reference to FIGS. 2A-2C, the surfacereactions (e.g., half-reactions) are done sequentially, and the variousprecursors and reactants are not in contact in embodiments. Prior tointroduction of a new precursor or reactant, the chamber in which theALD process takes place may be purged with an inert carrier gas (such asnitrogen or air) to remove any unreacted precursor and/orsurface-precursor reaction byproducts. The precursors will be differentfor each layer and the second precursor for the yttrium-containing oxidelayer or other rare-earth metal-containing oxide layer may be a mixtureof two rare earth metal-containing oxide precursors to facilitateco-deposition of these compounds to form a single phase material layer.In some embodiments, at least two precursors are used, in otherembodiments at least three precursors are used and in yet furtherembodiments at least four precursors are used.

ALD processes may be conducted at various temperatures depending on thetype of process. The optimal temperature range for a particular ALDprocess is referred to as the “ALD temperature window.” Temperaturesbelow the ALD temperature window may result in poor growth rates andnon-ALD type deposition. Temperatures above the ALD temperature windowmay result in reactions taken place via a chemical vapor deposition(CVD) mechanism. The ALD temperature window may range from about 100° C.to about 400° C. In some embodiments, the ALD temperature window isbetween about 120-300° C.

The ALD process allows for a conformal plasma resistant coating havinguniform thickness on articles and surfaces having complex geometricshapes, holes with high aspect ratios, and three-dimensional structures.Sufficient exposure time of each precursor to the surface enables theprecursor to disperse and fully react with the surface in its entirety,including all of its three-dimensional complex features. The exposuretime utilized to obtain conformal ALD in high aspect ratio structures isproportionate to the square of the aspect ratio and can be predictedusing modeling techniques. Additionally, the ALD technique isadvantageous over other commonly used coating techniques because itallows in-situ on demand material synthesis of a particular compositionor formulation without the need for a lengthy and difficult fabricationof source materials (such as powder feedstock and sintered targets). Insome embodiments ALD is used to coat articles aspect ratios of about10:1 to about 300:1.

With the ALD techniques described herein, multi-component films such asY_(x)Al_(y)O_(z) (e.g., Y₃Al₅O₁₂), Y_(x)Zr_(y)O_(z), andY_(a)Zr_(x)Al_(y)O_(z), Y_(x)Er_(y)O_(z), Y_(x)Er_(y)F_(z), orY_(w)Er_(x)O_(y)F_(z) can be grown, deposited or co-deposited, forexample, by proper mixtures of the precursors used to grow therare-earth metal-containing oxides alone or in combination with one ormore other oxides as described above and in more detail in the examplesbelow.

FIG. 3A illustrates a method 300 for forming a plasma resistant coatingcomprising a stress relief layer and a rare-earth metal-containing oxidelayer on an article such as a process chamber component according toembodiments. Method 300 may be used to coat any articles includingarticles having aspect ratios of about 3:1 to about 300:1 (e.g., aspectratios of 20:1, 50:1, 100:1, 150:1, and so on). The method mayoptionally begin by selecting a composition for the stress relief layerand for the yttrium-containing oxide layer of the plasma resistantcoating. The composition selection and method of forming may beperformed by the same entity or by multiple entities.

The method may optionally include, at block 305, cleaning the articlewith an acid solution. In one embodiment, the article is bathed in abath of the acid solution. The acid solution may be a hydrofluoric acid(HF) solution, a hydrochloric acid (HCl) solution, a nitric acid (HNO₃)solution, or combination thereof in embodiments. The acid solution mayremove surface contaminants from the article and/or may remove an oxidefrom the surface of the article. Cleaning the article with the acidsolution may improve a quality of a coating deposited using ALD. In oneembodiment, an acid solution containing approximately 0.1-5.0 vol % HFis used to clean chamber components made of quartz. In one embodiment,an acid solution containing approximately 0.1-20 vol % HCl is used toclean articles made of Al₂O₃. In one embodiment, an acid solutioncontaining approximately 5-15 vol % HNO₃ is used to clean articles madeof aluminum and other metals.

At block 310, the article is loaded into an ALD deposition chamber. Atblock 320, the method comprises depositing a plasma resistant coatingonto a surface of the article using ALD. In one embodiment, at block 325ALD is performed to deposit a stress relief layer. In one embodiment, atblock 330 ALD is performed to deposit or co-deposit a rare-earthmetal-containing oxide layer alone or together with one or more otheroxides. ALD is a very conformal process as performed in embodiments,which may cause the surface roughness of the plasma resistant coating tomatch a surface roughness of an underlying surface of the article thatis coated. The plasma resistant coating may have a total thickness ofabout 20 nm to about 10 μm in some embodiments. In other embodiments,the plasma resistant coating may have a thickness of about 100 nm toabout 2 micron. The plasma resistant coating may have a porosity ofabout 0% in embodiments, or may be porosity-free in embodiments, and mayhave a thickness variation of about ±5% or less, ±10% or less, or ±20%or less.

In one embodiment, at block 335 ALD is performed to deposit a stack ofalternating layers of the rare-earth metal containing oxide and anadditional oxide. The additional oxide may be the same as or differentfrom an oxide used for the stress relief layer.

A yttrium-containing oxide layer includes a yttrium-containing oxide andmay include one or more additional rare earth metal oxides. Rare earthmeatal-containing oxide materials that include yttrium may be used toform the plasma resistant coating in embodiments becauseyttrium-containing oxides generally have high stability, high hardness,and superior erosion resistant properties. For example, Y₂O₃ is one ofthe most stable oxides and has a standard Gibbs free energy of formation(ΔG_(f)°) of −1816.65 kJ/mol, indicating the reactions of Y₂O₃ with mostof the process chemicals are thermodynamically unfavorable understandard conditions. Plasma resistant coatings that include the stressrelief layer and rare-earth metal-containing oxide layer with Y₂O₃deposited in accordance with embodiments herein may also have a lowerosion rate to many plasma and chemistry environments, such as anerosion rate of about 0 μm/hr when exposed to a direct NF₃ plasmachemistry at a bias of 200 Watts and 500° C. For example, a 1 hour testof direct NF₃ plasma at 200 Watts and 500° C. caused no measureableerosion. The plasma resistant coatings deposited in accordance withembodiments herein may also be resistant to cracking and delamination attemperatures up to about 250° C. in embodiments, or up to about 200° C.in embodiments, or from about 200° C. to about 250° C. in furtherembodiments. In contrast, coatings formed using conventional plasmaspray coating or ion assisted deposition form cracks upon deposition andat temperatures at or below 200° C.

Examples of yttrium-containing oxide compounds that the plasma resistantcoating may be formed of include Y₂O₃, Y_(x)Al_(y)O_(z) (e.g.,Y₃Al₅O₁₂), Y_(x)Zr_(y)O_(z), Y_(a)Zr_(x)Al_(y)O_(z), orY_(x)Er_(y)O_(z). The yttrium content in the plasma resistant coatingmay range from about 0.1 at. % to close to 100 at. %. Foryttrium-containing oxides, the yttrium content may range from about 0.1at. % to close to 100 at. % and the oxygen content may range from about0.1 at. % to close to 100 at. %.

Examples of erbium-containing oxide compounds that the plasma resistantcoating may be formed of include Er₂O₃, Er_(x)Al_(y)O_(z) (e.g.,Er₃Al₅O₁₂), Er_(x)Zr_(y)O_(z), Er_(a)Zr_(x)Al_(y)O_(z),Y_(x)Er_(y)O_(z), and Er_(a)Y_(x)Zr_(y)O_(z) (e.g., a single phase solidsolution of Y₂O₃, ZrO₂ and Er₂O₃). The erbium content in the plasmaresistant coating may range from about 0.1 at. % to close to 100 at. %.For erbium-containing oxides, the erbium content may range from about0.1 at. % to close to 100 at. % and the oxygen content may range fromabout 0.1 at. % to close to 100 at. %.

Advantageously, Y₂O₃ and Er₂O₃ are miscible. A single phase solidsolution can be formed for any combination of Y₂O₃ and Er₂O₃. Forexample, a mixture of just over 0 mol % Er₂O₃ and just under 100 mol %Y₂O₃ may be combined and co-deposited to form a plasma resistant coatingthat is a single phase solid solution. Additionally, a mixture of justover 0 mol % E₂O₃ and just under 100 mol % Y₂O₃ may be combined to forma plasma resistant coating that is a single phase solid solution. Plasmaresistant coatings of Y_(x)Er_(y)O_(z) may contain between over 0 mol %to under 100 mol % Y₂O₃ and over 0 mol % to under 100 mol % Er₂O₃. Somenotable examples include 90-99 mol % Y₂O₃ and 1-10 mol % Er₂O₃, 80-89mol % Y₂O₃ and 11-20 mol % Er₂O₃, 70-79 mol % Y₂O₃ and 21-30 mol %Er₂O₃, 60-69 mol % Y₂O₃ and 31-40 mol % Er₂O₃, 50-59 mol % Y₂O₃ and41-50 mol % Er₂O₃, 40-49 mol % Y₂O₃ and 51-60 mol % Er₂O₃, 30-39 mol %Y₂O₃ and 61-70 mol % Er₂O₃, 20-29 mol % Y₂O₃ and 71-80 mol % Er₂O₃,10-19 mol % Y₂O₃ and 81-90 mol % Er₂O₃, and 1-10 mol % Y₂O₃ and 90-99mol % Er₂O₃. The single phase solid solution of Y_(x)Er_(y)O_(z) mayhave a monoclinic cubic state at temperatures below about 2330° C.

Advantageously, ZrO₂ may be combined with Y₂O₃ and Er₂O₃ to form asingle phase solid solution containing a mixture of the ZrO₂, Y₂O₃ andEr₂O₃ (e.g., Er_(a)Y_(x)Zr_(y)O_(z)). The solid solution ofY_(a)Er_(x)Zr_(y)O_(z) may have a cubic, hexagonal, tetragonal and/orcubic fluorite structure. The solid solution of Y_(a)Er_(x)Zr_(y)O_(z)may contain over 0 mol % to 60 mol % ZrO₂, over 0 mol % to 99 mol %Er₂O₃, and over 0 mol % to 99 mol % Y₂O₃. Some notable amounts of ZrO₂that may be used include 2 mol %, 5 mol %, 10 mol %, 15 mol %, 20 mol %,30 mol %, 50 mol % and 60 mol %. Some notable amounts of Er₂O₃ and/orY₂O₃ that may be used include 10 mol %, 20 mol %, 30 mol %, 40 mol %, 50mol %, 60 mol %, 70 mol %, 80 mol %, and 90 mol %.

Plasma resistant coatings of Y_(a)Zr_(x)Al_(y)O_(z) may contain over 0%to 60 mol % ZrO₂, over 0 mol % to 99 mol % Y₂O₃, and over 0 mol % to 60mol % Al₂O₃. Some notable amounts of ZrO₂ that may be used include 2 mol%, 5 mol %, 10 mol %, 15 mol %, 20 mol %, 30 mol %, 50 mol % and 60 mol%. Some notable amounts of Y₂O₃ that may be used include 10 mol %, 20mol %, 30 mol %, 40 mol %, 50 mol %, 60 mol %, 70 mol %, 80 mol %, and90 mol %. Some notable amounts of Al₂O₃ that may be used include 2 mol%, 5 mol %, 10 mol %, 20 mol %, 30 mol %, 40 mol %, 50 mol % and 60 mol%. In one example, the plasma resistant coating ofY_(a)Zr_(x)Al_(y)O_(z) contains 42 mol % Y₂O₃, 40 mol % ZrO₂ and 18 mol% Y₂O₃ and has a lamellar structure. In another example, the plasmaresistant coating of Y_(a)Zr_(x)Al_(y)O_(z) contains 63 mol % Y₂O₃, 10mol % ZrO₂ and 27 mol % Er₂O₃ and has a lamellar structure.

In embodiments, a plasma resistant coating that includes the stressrelief layer and the rare-earth metal-containing oxide layer of Y₂O₃,Y_(x)Al_(y)O_(z) (e.g., Y₃Al₅O₁₂), Y_(x)Zr_(y)O_(z),Y_(a)Zr_(x)Al_(y)O_(z), or Y_(x)Er_(y)O_(z) has a low outgas sing rate,a dielectric breakdown voltage on the order of about 1000 V/μm, ahermiticity (leak rate) of less than about 1 E-8 Torr/s, a Vickershardness of about 600 to about 950 or about 685, an adhesion of about 75mN to about 100 mN or about 85 mN as measured by the scratch test and afilm stress of about −1000 to −2000 MPa (e.g., about −1140 MPa) asmeasured by x-ray diffraction at room temperature.

FIG. 3B illustrates a method 350 for forming a yttrium-containing oxideplasma resistant coating on an aluminum article (e.g., Al6061, orAl6063) such as a process chamber component according to an embodiment.The method may optionally begin by selecting compositions for the plasmaresistant coating. The composition selection and method of forming maybe performed by the same entity or by multiple entities.

At block 352 of method 350, a surface of the article (e.g., of theprocess chamber component) is cleaned using an acid solution. The acidsolution may be any of the acid solutions described above with referenceto block 305 of method 300. The article may then be loaded into an ALDdeposition chamber.

Pursuant to block 355, the method comprises depositing a first layer ofamorphous Al₂O₃ onto a surface of an article via ALD. The amorphousAl₂O₃ may have a thickness of about 10 nm to about 1.5 μm. Pursuant toblock 360, the method further comprises forming a second layer byco-depositing (i.e., in one step) a mixture of a yttrium-containingoxide precursor and another oxide precursor onto the amorphous Al₂O₃stress relief layer via ALD. The second layer may include Y₂O₃ in asingle phase with Al₂O₃ or Er₂O₃or ZrO₂, for example. Alternatively, thesecond layer may include multiple phases, such as a phase of Y₄Al₂O₉ andanother phase comprising a solid-solution of Y₂O₃—ZrO₂

In some embodiments, the stress relief layer may be formed from analuminum oxide precursor selected from diethylaluminum ethoxide,tris(ethylmethylamido)aluminum, aluminum sec-butoxide, aluminumtribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum,trimethylaluminum, or tris(diethylamido)aluminum for ALD.

In some embodiments, the rare-earth metal-containing oxide layer is orincludes yttria, and the yttrium oxide precursor used to form therare-earth metal-containing oxide layer may be selected from or includetris(N,N-bis(trimethylsilyl)amide)yttrium (III) or yttrium (III)butoxidefor the ALD.

In some embodiments the rare earth metal-containing oxide layer includeszirconium oxide. When the rare-earth metal-containing oxide layercomprises zirconium oxide, a zirconium oxide precursor may includezirconium (IV) bromide, zirconium (IV) chloride, zirconium (IV)tert-butoxide, tetrakis(diethylamido)zirconium (IV),tetrakis(dimethylamido)zirconium (IV), ortetrakis(ethylmethylamido)zirconium (IV) for ALD. One or more of thesezirconium oxide precursors may be co-deposited with a yttrium oxideprecursor.

In some embodiments, the rare-earth metal-containing oxide layer mayfurther include an erbium oxide. An erbium oxide precursor may beselected from tris-methylcyclopentadienyl erbium(III) (Er(MeCp)₃),erbium boranamide (Er(BA)₃), Er(TMHD)₃,erbium(III)tris(2,2,6,6-tetramethyl-3,5-heptanedionate), ortris(butylcyclopentadienyl)erbium(III) for ALD.

As discussed above, the rare-earth metal-containing oxide layer mayinclude a mixture of multiple different oxides. To form such arare-earth metal-containing oxide layer, any combination of theaforementioned yttria precursors, erbium oxide precursors, aluminaprecursors and/or zirconium oxide precursors may be introduced togetherinto an ALD deposition chamber to co-deposit the various oxides and forma layer having a single phase or multiple phases. The ALD deposition orco-deposition may be performed in the presence of ozone, water,O-radicals, or other precursors that may function as oxygen donors.

At block 370, a determination may be made as to whether additionallayers are to be added (e.g., if a multi-layer stack is to be formed).If additional layers are to be added, then the method may return toblock 355 and an additional layer of Al2O3 may be formed. Otherwise themethod may proceed to block 375.

At block 375, the article (e.g., the chamber component) and both layersof the plasma resistant coating on the chamber component are heated. Theheating may be via an annealing process, a thermal cycling processand/or via a manufacturing step during semiconductor processing. In oneembodiment, the thermal cycling process is performed on coupons as acheck after manufacture to detect cracks for quality control, where thecoupons are cycled to the highest temperature that a part may experienceduring processing. The thermal cycling temperature depends on a specificapplication or applications that the part will be used for. For athermal pie, for example (shown in FIG. 4C), coupons may be cycledbetween room temperature and 250° C. The temperature may be selectedbased on the material of construction of the article, surface, and filmlayers so as to maintain their integrity and refrain from deforming,decomposing, or melting any or all of these components.

FIGS. 4A-4C depict variations of a plasma resistant coating according todifferent embodiments. FIG. 4A illustrates a multi-layer plasmaresistant coating for a surface 405 of an article 410 according to anembodiment. Surface 405 may be the surface of various articles 410.

For example, articles 410 may include various semiconductor processchamber components including but not limited to substrate supportassembly, an electrostatic chuck (ESC), a ring (e.g., a process kit ringor single ring), a chamber wall, a base, a gas distribution plate, gaslines, a showerhead, a nozzle, a lid, a liner, a liner kit, a shield, aplasma screen, a flow equalizer, a cooling base, a chamber viewport, achamber lid, and so on. The semiconductor process chamber component maybe made from a metal (such as aluminum, stainless steel), a ceramic, ametal-ceramic composite, a polymer, a polymer ceramic composite, orother suitable materials, and may further comprise materials such as AN,Si, SiC, Al₂O₃, SiO₂, and so on.

In FIG. 4A, the bi-layer coating composition comprises a stress relieflayer of an amorphous aluminum oxide coated onto surface 405 of article410 using an ALD process and a rare-earth metal-containing oxide layercoated onto the stress relief layer of article 410 using an ALD process.

FIG. 4A illustrates a bottom view of a showerhead 400. The showerheadexample provided below is just an exemplary chamber component whoseperformance may be improved by the use of the plasma resistant coatingas set forth in embodiments herein. It is to be understood that theperformance of other chamber components may also be improved when coatedwith the plasma resistant coating disclosed herein. The showerhead 400,as depicted here, was chosen as an illustration of a semiconductorprocess chamber component having a surface with complex geometry andholes with high aspect ratios.

The complex geometry of lower surface 405 may receive a plasma resistantcoating according to embodiments herein. Lower surface 405 of showerhead400 defines gas conduits 410 arranged in evenly distributed concentricrings. In other embodiments, gas conduits 410 may be configured inalternative geometric configurations and may have as many or as few gasconduits as needed depending on the type of reactor and/or processutilized. The plasma resistant coating is grown or deposited on surface405 and in gas conduit holes 410 using the ALD technique which enables aconformal coating of relatively uniform thickness and zero porosity(i.e., porosity-free) on the surface as well as in the gas conduit holesdespite the complex geometry and the large aspect ratios of the holes.

Showerhead 400 may be exposed to corrosive chemistries such as fluorineand may erode due to plasma interaction with the showerhead. The plasmaresistant coating may reduce such plasma interactions and improve theshowerhead's durability. Conformal coating is important for surfacesexposed to plasma as the coated/uncoated boundaries are prone to arcingin a capacitive-couple plasma environment. The plasma resistant coatingdeposited with ALD maintains the relative shape and geometricconfiguration of the lower surface 405 and of the gas conduits 410 so asto not disturb the functionality of the showerhead. Similarly, whenapplied to other chamber components, the plasma resistant coating maymaintain the shape and geometric configuration of the surface it isintended to coat so as to not disturb the component's functionality,provide plasma resistance, and improve erosion and/or corrosionresistance throughout the entire surface.

The resistance of the coating material to plasma is measured through“etch rate” (ER), which may have units of micron/hour (μm/hr),throughout the duration of the coated components' operation and exposureto plasma. Measurements may be taken after different processing times.For example, measurements may be taken before processing, after 50processing hours, after 150 processing hours, after 200 processinghours, and so on. Variations in the composition of the plasma resistantcoating grown or deposited on the showerhead or on any other processchamber component may result in multiple different plasma resistances orerosion rate values. Additionally, a plasma resistant coating with asingle composition exposed to various plasmas could have multipledifferent plasma resistances or erosion rate values. For example, aplasma resistant material may have a first plasma resistance or erosionrate associated with a first type of plasma and a second plasmaresistance or erosion rate associated with a second type of plasma. Inembodiments, no detectable etching occurred after exposure to a 200 WNF₃ direct plasma at 500C for 1 hours.

FIG. 4B depicts a blown up view of a gas conduit 410 having a highaspect ratio coated according to an embodiment. Gas conduit 410 may havea length L and a diameter D. Gas conduit 410 may have a high aspectratio defined as L:D, wherein the aspect ratio may range from about 10:1to about 300:1. In some embodiments, the aspect ratio may be about 50:1to about 100:1.

Gas conduit 410 may have an interior surface 455 which may be coatedwith a plasma resistant coating. The plasma resistant coating maycomprise a stress relief layer 460 and a rare earth metal-containingoxide layer 465. The stress relief layer 460 may comprise an amorphousAl₂O₃. The rare earth metal-containing oxide layer 465 may comprise apolycrystalline yttrium oxide alone or together with an additional rareearth metal oxide (e.g., erbium oxide, zirconium oxide, etc.). The rareearth metal-containing oxide layer 465 may have any rare earthmetal-containing oxide material such as those described herein above.Each layer may be coated using an ALD process. The ALD process may growconformal coating layers of uniform thickness that are porosity-freethroughout the interior surface of gas conduit 410 despite its highaspect ratio while ensuring that the final multi-component coating mayalso be thin enough so as to not plug the gas conduits in theshowerhead.

In some embodiments, each layer may comprise monolayers or thin layersof uniform thickness. Each monolayer or thin layer may have a thicknessranging from about 0.1 nanometers to about 100 nanometers. In otherembodiments, the layers may comprise thick layers of uniform thickness.Each thick layer may have a thickness ranging from about 100 nanometersto about 1.5 micrometer. In yet other embodiments, the layers maycomprise a combination of monolayers, thin layers and/or thick layers.

FIG. 4C depicts a thermal pie chamber component 470, in accordance withembodiments. The thermal pie chamber component 470 includes a plasmaresistant coating as described in embodiments herein. A thermal pie isone of eight mutually isolated showerheads used in a spatial ALDchamber. Some of the eight showerheads are plasma pies and some arethermal pies. Wafers are positioned under these showerheads duringprocessing, and move past each of them and get exposed to differentchemicals and plasmas that these showerheads provide sequentially. Inone embodiment, the thermal pie has 10:1 aspect ratio holes 475 and isexposed to harsh chemicals.

The following examples are set forth to assist in understanding theembodiments described herein and should not be construed as specificallylimiting the embodiments described and claimed herein. Such variations,including the substitution of all equivalents now known or laterdeveloped, which would be within the purview of those skilled in theart, and changes in formulation or minor changes in experimental design,are to be considered to fall within the scope of the embodimentsincorporated herein. These examples may be achieved by performing method300 or method 350 described above.

Example 1 Forming an Al₂O₃ Stress Relief Layer on an Al 6061 Substrateand Coating the Stress Relief Layer with a Y₂O₃-Containing Coating

A plasma resistant coating was deposited on an aluminum substrate of Al6061 (e.g, at a temperature of about room temperature to about 300° C.).A stress relief layer of amorphous aluminum oxide was deposited on thealuminum substrate using atomic layer deposition. The precursor for thestress relief layer was introduced to the substrate at a pressure on thescale of one or a few mtorr to one or a few torr and a temperature ofabout 100-250° C. Subsequently, a polycrystalline yttrium-containingoxide layer was deposited on the stress relief layer using atomic layerdeposition. The precursor for the yttrium-containing oxide layer wasintroduced to the substrate at a pressure on the scale of one or a fewmtorr to one or a few torr and a temperature of about 100-250° C.

The resulting plasma resistant coating on the aluminum substrate wascharacterized using inter alia transmission electron microscopy. Thethickness of the stress relief layer was about 5 nm to about 15 nm andthe thickness of the yttrium-containing oxide layer was about 90 nm toabout 110 nm.

Selective area diffraction and Convergence beam electron diffraction wasused to determine the structure of the material in each layer. Thealuminum oxide in the stress relief layer had an amorphous structurewhereas the yttrium-containing oxide layer had a poly-crystallinestructure. The aluminum substrate both pre- and post-coating wascharacterized using scanning electron microscopy (SEM). The SEM imagesshowed that the plasma resistant coating covered all of the features onthe aluminum substrate.

The breakdown voltage of the coated substrate was also measured. Thebreakdown voltage was from about 305 to about 560 for 1 μm yttria. Inembodiments, the breakdown voltage of the plasma resistant ceramiccoating is lower than an intrinsic breakdown voltage for the ceramicsused to form the plasma resistant ceramic coating. The coated substratewas also exposed to a NF₃ direct plasma at 500° C., 200 W. No observableetching or surface deterioration was observed due to reaction with theNF₃ plasma.

The coated substrate was also subjected to five (5) thermal cycles at200° C. SEM images showed that there were no cracks in the coatingwhereas with conventional plasma spray or ion assisted depositioncoatings, cracks would be observed. The hardness of the coated substratewas also evaluated. The substrate had a Vickers hardness of about 500 toabout 830 or about 626.58±98.91, or of about 5,500 MPa to about 9,000MPa or about 6,766±1,068. The coated substrate had a Young's modulus ofabout 75 GPa to about 105 GPa or about 91.59±8.23 GPa. The coatedsubstrate exhibited a maximum hardness at about 0.110 μm to about 0.135μm or about 0.125±0.007 μm.

The adhesion of the coating to the aluminum substrate was measured by ascratch test. The first delamination Lc occurred at about 75 to about100 mN or about 85.17±9.59. The film stress of the coated substrate wasmeasured by x-ray diffraction at room temperature. The film stress wasabout −1140 MPa or about −165.4 (KSi).

FIG. 5 shows the results 500 of an outgassing comparison test at 125° C.in total mass loss (μg/cm²) as a function of time (minutes). Thefollowing materials were compared: a bulk yttria material with a three(3) hour bake 505, a polysilicon and yttria material with a three (3)hour bake 510, a Dura HPM material with a three (3) hour bake 515, aBare SST material with a three (3) hour bake 520, aluminum oxidedeposited on aluminum 1500 nm as coated using ALD 525 and a Parylene® HTon a stainless steel (SST) material 530. As shown in FIG. 5, the aluminadeposited on aluminum 525 had a relatively low outgassing.

Example 2 Plasma Resistant Coating Having Rare-Earth Oxide-ContainingLayer with Y₂O₃/Al₂O₃ Alternating Sub-Layers Over Al₂O₃ Layer on an Al6061 Substrate After 350° C. Thermal Cycling

FIG. 6 shows an image of a coated substrate 605 as generated bytransmission electron spectroscopy (TEM). The substrate 605 wascomprised of aluminum (Al6061). A stress relief layer 610 of amorphousaluminum oxide was deposited on the substrate 605 using ALD. A rareearth oxide-containing layer 615 that includes alternating Y₂O₃ andAl₂O₃ sublayers was deposited over the stress relief layer 610. Thesubstrate 605 includes a pit 630. As shown, the layers 610, 615 provideconformal coverage of the pit 630. For example, a channel 632 in the pit630 was sealed by the stress relief layer 610. A remainder of the pit630 was then sealed by the rare-earth metal-containing oxide layer 615.The substrate 605 with the stress relief layer 610 and rare-earthmetal-containing oxide layer 615 was then subjected to thermal cyclingat 350° C. without any cracking or delamination. A capping layer 620 isshown, which is placed on the sample for the TEM image. However, thecapping layer 620 is not used for production parts.

FIG. 7A depicts a top down SEM image of a plasma resistant coating asdescribed herein. FIG. 7B depicts a TEM cross sectional image of theplasma resistant coating of FIG. 7A. The images include a top down image705 and a cross sectional side view image 710 taken from a coupon cutout from a region 708 depicted in the top down image. As shown in thecross sectional side view image 710, an article 715 includes a plasmaresistant coating that includes a stress relief layer 720 and a rareearth oxide layer 725. The rare earth oxide layer has a thickness ofabout 600 nm and the stress relief layer has a thickness of about 200nm. The TEM images were taken after thermal cycling was performedbetween room temperature and temperatures of 200° C. As shown, nocracking occurred in the plasma resistant coating as a result of thethermal cycling and the plasma resistant coating is not delaminatingfrom the article. Similar tests have shown corresponding results of nocracking or delamination after thermal cycling of 250° C. and 300° C.

FIG. 8A depicts a top down SEM image of an ALD coating 804 of Y₂O₃without an Al₂O₃ stress relief layer on an article. FIG. 8B depicts across sectional image of the ALD coating 804 of FIG. 8A on the article802. As shown, cracks 805 formed in the Y₂O₃ coating 804 after thermalcycling.

FIG. 9 illustrates a cross sectional side view TEM image of a plasmaresistant ceramic sample as described with regards to FIG. 2C. Thesample was imaged with a FEI Tecnai TF-20 FEG/TEM operated at 200 kV inbright-field (BF) TEM mode. As shown, the sample includes an article 910with a plasma resistant coating that includes a stress relief layer 915having a thickness of about 20 nm and rare-earth metal-containing oxidelayer 920 that includes a stack of alternating sub-layers, the stackhaving a thickness of about 134 nm. A crystalline contrast from theparticles can be seen in the stack 920 of alternating layers. However,the stack 920 of alternating layers is mostly amorphous with short rangeorder in the illustrated TEM image.

FIG. 10 is a scanning transmission electron microscopy energy-dispersivex-ray spectroscopy (STEM-EDS) line scan of the plasma resistant ceramicsample shown in FIG. 9. As shown, the article 910 is aluminum 6061substrate. The stress relief layer 915 includes about 60-80 atom %oxygen 1010 and about 20-40 atom % aluminum 1025. The rare-earthmetal-containing oxide layer 920 is composed primarily of oxygen 1010and yttrium 1015, with about 5 atom % aluminum.

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent invention. It will be apparent to one skilled in the art,however, that at least some embodiments of the present invention may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present invention. Thus, the specific details set forth are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the scope of the presentinvention.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” When the term “about” or “approximately” is usedherein, this is intended to mean that the nominal value presented isprecise within ±10 %.

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of the invention should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. An article comprising: a channel or conduithaving an aspect ratio of length to width diameter of about 3:1 to about300:1; and a plasma resistant coating on a surface of the channel orconduit of the article, wherein the plasma resistant coating comprises:a stress relief layer having a thickness of about 10 nm to about 1.5 μm;and a rare earth metal-containing oxide layer having a thickness ofabout 10 nm to about 1.5 μm, wherein the rare earth metal-containingoxide layer covers the stress relief layer, and wherein the rare earthmetal-containing oxide layer comprises a material selected from a groupconsisting of Y₃Al₅O₁₂ (YAG), Er₂O₃, Er₃Al₅O₁₂ (EAG), Gd₂O₃, a solidsolution of Y₂O₃—ZrO₂ comprising 10 mol % to 90 mol % Y₂O₃ and 10 mol %to 90 mol % ZrO₂, and a ceramic compound comprising Y₄Al₂O₉ or asolid-solution of Y₂O₃—ZrO₂; wherein the plasma resistant coatinguniformly covers the channel or conduit, is resistant to cracking anddelamination at a temperature of up to 350° C. and is porosity-free. 2.The article of claim 1, wherein the article is a chamber componentselected from a group consisting of a chamber wall, a plasma generationunit, a shower head, a diffuser, a nozzle, gas distribution hub assemblyand a gas line.
 3. The article of claim 1, wherein the aspect ratio isabout 10:1 to about 200:1.
 4. The article of claim 1, wherein the stressrelief layer comprises amorphous Al₂O₃, and wherein the stress relieflayer is a barrier to prevent diffusion of impurities from the article.5. (canceled)
 6. The article of claim 1, wherein the rare earthmetal-containing oxide layer comprises a mixture of about 0.1 mol % toabout 90 mol % Y₂O₃ and about 0.1 mol % to about 90 mol % of anothermetal oxide.
 7. The article of claim 1, wherein the rare earthmetal-containing oxide layer has a polycrystalline structure.
 8. Thearticle of claim 1, further comprising: a stack of alternating layers ofthe rare earth metal-containing oxide and a second oxide, wherein: afirst layer in the stack of alternating layers is the rare earthmetal-containing oxide layer; layers of the rare earth metal-containingoxide each have a thickness of about 5-100 angstroms; and layers of thesecond oxide each have a thickness of about 1-20 angstroms, where thelayers of the second oxide prevent crystal formation in the layers ofthe rare earth metal-containing oxide.
 9. The article of claim 8,wherein: the layers of the second oxide have a same material compositionas the stress relief layer; the stress relief layer has a thickness ofabout 10 nm-1.5 μm; and the stack of alternating layers has a totalthickness of about 10 nm-1.5 μm.
 10. A method comprising: depositing aplasma resistant coating onto a surface of a chamber component using anatomic layer deposition process, comprising: depositing a stress relieflayer on the surface using atomic layer deposition to a thickness ofabout 10 nm to about 1.5 μm; and depositing a rare-earthmetal-containing oxide layer on the stress relief layer using atomiclayer deposition to a thickness of about 10 nm to about 1.5 μm, whereinthe rare earth metal-containing oxide layer comprises a materialselected from a group consisting of Y₃Al₅O₁₂ (YAG), Er₂O₃, Er₃Al₅O₁₂(EAG), Gd₂O₃, a solid solution of Y₂O₃—ZrO₂ comprising 10 mol % to 90mol % Y₂O₃ and 10 mol % to 90 mol % ZrO₂, and a ceramic compoundcomprising Y₄Al₂O₉ or a solid-solution of Y₂O₃—ZrO₂; wherein the plasmaresistant coating uniformly covers the surface of the chamber component,is resistant to cracking and delamination at a temperature of up to 350°C. and is porosity-free.
 11. The method of claim 10, wherein depositingthe stress relief layer comprises depositing amorphous aluminum oxide.12. The method of claim 10, wherein depositing the rare-earthmetal-containing oxide layer comprises depositing a yttrium-containingoxide by: performing a deposition cycle comprising: injecting ayttrium-containing precursor into a deposition chamber containing thechamber component to cause the yttrium-containing precursor to adsorbonto a surface of the stress relief layer to form a first half reaction;and injecting an oxygen-containing reactant into the deposition chamberto form a second half reaction; and repeating the deposition cycle oneor more times until a target thickness is achieved.
 13. The method ofclaim 10, wherein depositing the rare-earth metal-containing oxide layercomprises alternating deposition of a yttrium-containing oxide and oneor more additional metal oxides to form a single phase or multi-phaseyttrium-containing oxide layer by: performing a deposition cyclecomprising: injecting a yttrium-containing precursor into a depositionchamber containing the chamber component to cause the yttrium-containingprecursor to adsorb onto a surface of the stress relief layer to form afirst half reaction; and injecting an oxygen-containing reactant intothe deposition chamber to form a second half reaction and a first layer;injecting a metal-containing precursor into the deposition chamber tocause the metal-containing precursor to adsorb onto a surface of thefirst layer to form a third half reaction; and injecting theoxygen-containing reactant or an alternative oxygen-containing reactantinto the deposition chamber to form a fourth half reaction; andrepeating the deposition cycle one or more times until a targetthickness is reached.
 14. The method of claim 10, wherein depositing therare-earth metal-containing oxide layer comprises co-depositing ayttrium-containing oxide and an additional metal oxide to form a singlephase or multi-phase yttrium-containing oxide layer by: performing adeposition cycle comprising: co-injecting a mixture of a first precursorfor the yttrium-containing oxide and a second precursor for theadditional metal oxide into a deposition chamber containing the chambercomponent to cause the first precursor and the second precursor toadsorb onto a surface of the stress relief layer to form a first halfreaction; and injecting an oxygen-containing reactant into thedeposition chamber to form a second half reaction; and repeating thedeposition cycle one or more times until a target thickness is reached.15. The method of claim 14, wherein the additional metal oxide isselected from a group consisting of Er₂O₃, Al₂O₃, and ZrO₂.
 16. Themethod of claim 14, wherein the yttrium-containing oxide layer comprisesa mixture of about 0 mol % to about 90 mol % Y₂O₃ and about 0.1 mol % toabout 90 mol % of the additional metal oxide.
 17. The method of claim14, wherein the yttrium-containing oxide layer is selected from a groupconsisting of Y₃Al₅O₁₂ (YAG), a solid solution of Y₂O₃—ZrO₂, and aceramic compound comprising Y₄Al₂O₉ and a solid-solution of Y₂O₃ 13ZrO₂.
 18. The method of claim 10, wherein the surface of the chambercomponent onto which the plasma resistant coating is deposited has anaspect ratio of length to width of about 10:1 to about 300:1, andwherein the plasma resistant coating uniformly covers the surface. 19.The method of claim 10, wherein the chamber component is a chambercomponent for a semiconductor processing chamber selected from a groupconsisting of a chamber wall, a shower head, a plasma generation unit, adiffuser, a nozzle, and a gas line.
 20. A method comprising: depositinga plasma resistant coating onto a surface of a chamber component usingan atomic layer deposition (ALD) process, comprising: depositing anamorphous stress relief layer on the surface using a plurality of cyclesof the ALD process to a thickness of about 10 nm to about 1.5 μm; anddepositing a stack of alternating layers of a rare earthmetal-containing oxide and a second oxide to a thickness of about 10 nmto about 1.5 μm, wherein each of the layers of the rare earthmetal-containing oxide are formed by performing about 1-30 cycles of theALD process, and wherein each of the layers of the second oxide areformed by performing 1-2 cycles of the ALD process, where the layers ofthe second oxide prevent crystal formation in the layers of the rareearth metal-containing oxide, and wherein the rare earthmetal-containing oxide comprises a material selected from a groupconsisting of Y₃Al₅O₁₂ (YAG), Er₂O₃, Er₃Al₅O₁₂ (EAG), Gd₂O₃, a solidsolution of Y₂O₃—ZrO₂ comprising 10 mol % to 90 mol % Y₂O₃ and 10 mol %to 90 mol % ZrO₂, and a ceramic compound comprising Y₄Al₂O₉ or asolid-solution of Y₂O₃—ZrO₂.
 21. The article of claim 2, wherein thearticle is a chamber component selected from a group consisting of aplasma generation unit, a shower head, a diffuser, a nozzle and a gasdistribution hub assembly.